The purpose of this project is to investigate the molecular structure of fibrous proteins and of proteoglycans and to study phosphorus chemistry in connective tissues. The structural information obtained will be correlated with function. Areas of present interest are 1) Structure of collagen and elastin. 13C and 2H magnetic resonance techniques are being used to study the structure and interactions in collagen and elastin fibers. 2) Proteoglycan structure. 13C magnetic resonance is also being used to study the molecular mobility of the polysaccharide and protein chains in the chick limb bud proteoglycan monomer. 3) Phosphorus chemistry in connective tissue. Magic angle spinning 31P magnetic resonance is being used to probe the structure of the phosphorus moieties in connective tissue. 4) 13C magnetic resonance is being used to study the extent and mechanism of hemoglobin S gelation in cell-free preparations and in erythrocytes. For these studies, magnetic resonance spectrometers have been assembled which give 2H, 13C, and 31P spectra of solids. High power decoupling, cross-polarization, magic angle spinning, and solid echo experiments are all performed.